[CalRobert]

Higher speeds generally increase traffic rather than decrease it, as following distance increases (or, if it doesn't, traffic due to wrecks will slow you down anyway).

That being said, I live in CA and would love a model much like Germany, with unrestricted freeways in the rural areas and speed limits around 15-20 mph in towns and cities. Going down I-5 to socal? Sure, do 150. Driving in a town where there could be people walking, cyclists, vehicles stopping often, etc,? Maybe 15 makes more sense.

Of course, not giving a license to just anyone with a pulse would be a start. My grandmother (lovely woman, but 91 and clearly past her driving years) failed her written driving test a few weeks ago. What did the DMV do? They _extended_ her license another two months, for reasons that escape me. "You can continue to drive despite a demonstrated ignorance of driving law" is pretty much what we're saying there.

Also, California is big. A lot of it probably resembles Iowa more than SF in terms of road infrastructure - ever head out to the more remote parts?

[hn9780470248775]

The German Autobahn (equivalent to Interstate highways here) is entirely limited-access, high-speed (minimum speed limit 100 km/h; often no speed limit).

The German Bundesstrasse (equivalent to U.S. or state highways?) does have highly variable speed limits, as you describe, and I found them correspondingly maddening to drive on, due to the incessant need to accelerate or decelerate.

[CalRobert]

Indeed - in my view this correlates to one of the best places in the world to drive. Variable limits seem more logical than assuming one speed can always be the best for current conditions. Road throughput (vehicle-miles per hour) can be maximized at a lower speed when traffic is heavy, so limits are reduced. Conversely, when traffic is light the minimization of individual travel time can be prioritized, so limits can be raised.